Conventionally, the above-described tractors or the wheel loaders generally have their engine mounted in a front portion of the traction unit chassis, and a transmission case mounted in a rear portion of the traction unit chassis, and the traction unit chassis is supported by front and rear wheels. In the above construction, the engine is mounted in a front portion of the traction unit chassis and the transmission case is disposed in a rear portion of the traction unit chassis (Patent Document 1 for example).
Further, the traction unit chassis includes an engine frame and a right and a left vehicle frames. The engine is mounted where the engine frame is connected with the vehicle frames while the transmission case is disposed between the right and left vehicle frames (Patent Document 2 for example).
Patent Document 1: JP-A-H11-334395
Patent Document 2: JP-A-2003-252236